Polysaccharides are relatively complex carbohydrates. They are polymers made up of many monosaccharides joined together by glycosidic bonds. They are therefore large, often branched, macromolecules. Polysaccharides, especially hyaluronic acid (HA), have been useful in cosmetic and medical applications. These polymers have been used, for example, as fillers in soft tissue augmentation.
Residing in the extracellular space, HA functions as a space-filling, structure stabilizing, and cell protective molecule with uniquely malleable physical properties and superb biocompatibility. HA matrices are extremely viscoelastic while preserving a high level of hydration. A strong correlation exists between the water content in the skin and levels of HA in dermal tissue. As human skin ages, there are known alterations in HA content and metabolism. With these changes, there is a significant deterioration in the mechanical properties of the skin. There appears to be a relationship between youthful skin and the presence of a strong HA network in the intercellular matrix.
Unfortunately, non-cross-linked as well as cross-linked polysaccharide chains such as HA are subject to degradation through different pathways; (e.g. enzymatic, free radical) thus limiting the polymer's longevity in vivo. It is, therefore, important to develop methods and compositions that decrease the rate of natural decomposition and increase the product's persistence in vivo. There remains an unmet need for having a polysaccharide formulation which has increased longevity by being resistant to degradation.